On the Announcements page, click the Announcements item that you want to edit.
Edit your Announcements posting.
To inform users of major changes and updates to postings that they might have dismissed, ensuring that those headlines reappear with current information, select the Major edit - send a notification and restore it for those who dismissed it check box. You can also make the edited Announcements posting reappear at the top of the Announcements widget by changing the start date to the current date and time.